Splicing tape, splicing method and splice using the splicing tape

ABSTRACT

A splicing tape (100) includes a splicing portion (1, 2) and an attachment portion (10&#34;, 41), the attachment portion (10&#34;, 41) being provided for releasably and self-supportively attaching the splicing tape (100) substantially across the width of a roll of sheet material. A first adhesive layer (2) is provided to attach the leading edge of the roll to the splicing tape (100). The attachment portion (10&#34;, 41) is adapted to release the leading edge and splicing portion (1, 2) from the underlying sheet material leaving a non-tacky first surface of the underlying sheet material. A butt or overlap splice can be completed by attaching a further sheet material to the splicing portion (1, 2). The attachment portion (10&#34;, 41) includes preferably portions (10&#34;) for separating the attachment portion from the splicing portion (1, 2) and/or portions (41) for detaching the attachment portion from the surface of the underlying layer. Methods of making permanent or flying splices are provided.

TECHNICAL FIELD

The present invention relates to permanent or flying splices betweensheet materials, a splicing tape for use in producing such splices andmethods of using the splicing tape in producing butt, and overlap,particularly staggered overlap splices.

BACKGROUND OF THE INVENTION

In this application and merely for clarity purposes the leading end andedge of a winding of sheet material on a roll is considered to be thefirst quadrant of sheet material exposed on the outside of the roll,i.e. the section 32 of sheet material shown in FIG. 3B from theimaginary line A--A' to the edge 35. The underlying winding 31 of such aroll is then the piece of sheet material on which the leading edge 35rests from A--A' through 360° to the position A--A' again.

Two common types of splice are known for webs of sheet materials.Firstly, there is a permanent splice for joining the leading edge of oneroll or part roll to the trailing edge of a further roll or part roll.The permanent splice should provide a flexible strong connection betweenthe two webs and should maintain substantially all of the properties ofthe sheet material, for example if the sheet material is paper which canbe printed or coated, the permanent splice is preferably, thin,flexible, printable, coatable and should also have the same repulpableproperties as paper. Conventional splicing tapes and splices do notgenerally meet all of these requirements. Further, when joining partrolls the second roll is normally wound back onto the first roll inorder to produce a complete roll and the permanent splice is thenlocated somewhere in the middle of the new larger roll. This splice issubject to high pressures caused by the winding tension and it isimportant that no adhesive materials are present either on or near thesplice or bleed out of the splice during storage which could adherelayers of sheet material together or damage or obstruct printingmachinery.

A typical permanent butt splice is shown in FIG. 1A. Such a splice canbe manufactured using a splicing tape as shown in FIG. 7 and describedin WO 90/08032.

A permanent overlap splice is also known as is shown in FIG. 1B. Herethe leading and trailing edges 3 and 4 of the first and second rolls arejoined together by a double sided tape of the kind shown in FIG. 8. Withreference to FIG. 3B the last winding 32 of the roll 30 is secured bysmall adhesive tabs 33 applied on both sides of the roll 30. One of therelease foils 10 (or 11) is then removed from the double sided tape 24to expose the pressure sensitive adhesive 2A (or 2B) and the tape isapplied across the width of the last winding 32 of the roll. The excessof the leading edge is folded back against the double sided tape and iscreased and torn off so that the final leading edge 35 abuts the doublesided adhesive tape 34 as shown in FIG. 3B. In this condition the rollmay be stored until a splice must be made. In order to complete thesplice the remaining release foil 11 (or 10) is removed thus exposingthe pressure sensitive adhesive 2B (or 2A) and the trailing edge of thesecond roll is then applied to the exposed pressure sensitive adhesive.The excess of the trailing edge is folded back to the adhesive join andis creased and torn off in the same way as described above with respectto the leading edge of the first roll. The splice now appears as in FIG.1B.

This type of splice has a disadvantage that there is a considerable stepat the change from the sheet material 3 or 4 and the splice itself whencompared with the butt splice shown in FIG. 1A. This step can disruptthe printing process. Further, there is the possibility of the adhesivebleeding out of the splice or bleeding through the paper if placed underpressure. Additionally, the webs of sheet material may move relative toeach other when tension in the web puts the splice in shear. If movementoccurs during multiple pass printing the alignment in successiveprinting stages is disturbed resulting in inferior quality. Any relativemovement is likely to release adhesive with the serious consequencesmentioned above. To prevent this movement an additional adhesive tape 6'is sometimes applied along the edge of the splice as shown in FIG. 1B.This improves the strength of the splice but increases its thicknessstill further.

Since a paper manufacturer is often held liable by the printer fordamage caused by the splice it is desirable to provide a reliablesplicing method and splice which does not affect the printing process.In particular a sheet surface with exposed aggressively tacky adhesiveis considered not to be machine printable.

In order to reduce the step at the splice, a staggered overlap splice asshown in FIG. 1C has been proposed in the non-prepublished documentEP-0555772 which can also be produced with a splicing tape shown in FIG.9. The splice in accordance with FIG. 1C may still suffer from thebleeding out problems of the overlap splice shown in FIG. 1B and has thefurther disadvantage that the leading edge of the first roll must be cutto a straight line before application of the tape rather than being ableto tear off the leading against the adhesive join as is possible withtapes shown in FIGS. 7 and 8. Splicing can also become necessary wheninsufficient sheet material is left on one drum. Webs from two drumsmust then be attached together Flying splices are usually temporarysplices made at machine running speeds between rolls when it isundesirable to stop the machine, e.g. during coating or printing. Thesurface speed of the roll can be 1000 or even 2000 meters per minute.The conventional way of making a flying splice can be understood fromFIG. 3A with reference to U.S. Pat. No. 4,564,150. Double sided adhesivetape 24 similar to that shown in FIG. 8 is applied to the last winding32 of a roll 30 of sheet material in the form of a W, a V or any othersuitable arrangement. The last winding 32 of sheet material is torn offagainst the adhesive tape 24 leaving small wings 23 which are secured bysmall pieces of adhesive tape to the underlying layer 31 of sheetmaterial. The adhesive tabs and the small wings 23 are important to holddown the noses of the last winding 32 of the sheet material when theroll is travelling at machine rotation speeds. It is important that aircannot enter beneath the leading edge 35 of the last winding 32 whichwould result in the roll unwinding itself at very high speeds whichcould cause damage to the equipment and danger to the operators. Inorder to prevent air entering beneath the leading edge 35 of the lastwinding 32, small adhesive tabs are sometimes applied not only at thenoses of the leading edge but also along the diagonal edges of theleading edge 35. Completion of the splice is described in U.S. Pat. No.4,564,150. The final splice appears as in FIG. 2B. The leading edge 3 ofthe new roll is attached to the trailing edge 4 of the old roll by meansof the double sided tape 1, 2A, 2B and the excess of the trailing edgeleft after cutting is indicated by 8.

One method of reducing the step height of an overlap splice is describedin U.S. Pat. No. 4,905,924. The splicing tape has no backing member. Thesplicing tape has a section for attachment to the underlying windingwhich can be torn off.

It is possible to make a flying butt splice with a butt splicing tape ofthe kind shown in FIG. 7. The splicing tape as shown in FIG. 7 would bemodified so that the adhesive area for attachment to the trailing edgeof the old roll is made considerably larger than the area of adhesiveavailable for attachment to the leading edge of the new roll. The finalsplice is shown in FIG. 2A in which the leading edge of the new roll hasbeen attached to the splicing tape via the pressure sensitive adhesive2B and the trailing edge of the old roll has been attached to thegreater area of pressure sensitive adhesive 2A leaving the excess of thetrailing edge 8 to trail behind.

Although the low step profile of the butt splice would be preferred forboth permanent and the flying splices, several disadvantages with theapplication of the tape have resulted in this tape not being widely usedfor either permanent or flying splices. Firstly, a tape of the kindshown in FIG. 7 must be stretched across the width of a roll which maybe 4 to 10 meters wide with the non-adhesive side of the backing Iadjacent to the roll. This is usually done by two or more operators whoprovisionally may tape the roll into its final position using smallpieces of adhesive tape. Such a procedure is time consuming and there isthe danger that the small pieces of tape are not removed afterapplication of the tape. Secondly, adhesive may be transferred from thetabs to the sheet material which can result in subsequent bondingbetween layers of the sheet material or fouling of rollers or otherparts of the printing machinery. Thirdly, flying butt splices have notfound favour because it is necessary to lift the leading edge of the newroll in order to apply such tapes. This lifting of the leading edgeallows air to enter between the leading end 22 of the new roll and theunderlying layer 21 of the roll and thus there is an increased danger ofthe leading edge lifting off from the roll when it has reached machinespeeds. The same problem of lifting the leading edge may also occur if astaggered overlap flying splice were to be made with the splicing tapeshown in FIG. 9.

In DE-A-033900, a modified flying butt splicing tape is proposed. Thissplice tape leaves an exposed surface of adhesive on the underlyingwinding of the roll at a distance of approximately one circumference ofthis roll from the actual splice. This exposed adhesive layer is capableof picking up sheet remnants or attaching itself to other objects orparts of the machinery which can disrupt smooth operation. In particularthe exposed adhesive is left on the radially outwardly facing surface(referred to in the rest of this application as the outer surface of alayer of sheet material on a roll) of the roll. The exposed tackyadhesive on the outer surface of the underlying winding may render thesheet material unsuitable for machine printing. Further once thesplicing tape has been temporarily attached to the roll it cannot berepositioned.

SUMMARY OF THE INVENTION

The present invention provides a splicing tape for splicing the leadingedge of a roll of sheet material to a further sheet material, eachwinding of said sheet material on said roll having an outer surfacefacing radially outwards away from said roll, comprising:

a splicing portion and a pre-formed attachment portion, characterized inthat said splicing portion comprises:

an elongate backing member;

an adhesive layer on said backing member, a first part layer of saidadhesive layer being provided for attachment of the leading edge of theroll of sheet material substantially across the width of said roll tosaid backing member and a second part layer of said adhesive layer beingfor attachment to said further sheet material;

and that said pre-formed attachment portion is connected to anddistributed along said splicing portion for releasable andself-supportive attachment of said splicing tape to the outer surface ofthe underlying winding of said roll of sheet material substantiallyacross the width of said roll, said attachment portion being adapted forreleasing at least said splicing portion from said underlying winding ofsaid roll while leaving the outer surface of said underlying winding ina non-tacky condition.

The present invention also provides a splice on the leading edge of aroll of sheet material for attachment to a further sheet material, eachwinding of said sheet material on said roll having an outer surfacefacing radially outwards from said roll, comprising:

a splicing portion and a pre-formed attachment portion, characterized inthat said splicing portion comprises:

an elongate backing member;

an adhesive layer on said backing member, a first part layer of saidadhesive layer attaching the leading edge of the roll of sheet materialsubstantially across the width of said roll to said backing member and asecond part layer of said adhesive layer being provided for attachmentto said further sheet material;

and that said pre-formed attachment portion is connected to anddistributed along said splicing portion and releasably andself-supportively attaching said splicing tape to the outer surface ofsaid underlying winding of said roll of sheet material substantiallyacross the width of said roll, said attachment portion being adapted forreleasing at least said splicing portion from said underlying winding ofsaid first roll while leaving the outer surface of said underlyingwinding in a non-tacky condition.

The present invention further provides a method for preparing a splicebetween the leading edge of a roll of sheet material and a further sheetmaterial using a splicing tape, each winding of said sheet material onsaid roll having an outer surface facing radially outwards away fromsaid roll, said splicing tape comprising:

a splicing portion and a pre-formed attachment portion, in which methodsaid splicing tape is attached to the outer surface of said underlyingwinding using said attachment portion substantially across the width ofsaid roll, characterized in that said splicing portion comprises:

an elongate backing member;

an adhesive layer on said backing member and covered by at least onerelease foil, a first part layer of said adhesive layer being providedfor attaching the leading edge of said roll of sheet materialsubstantially across the width of said roll to said backing member and asecond part layer of said adhesive layer being provided for attachmentto said further sheet material;

that said pre-formed attachment portion is connected to and distributedalong said splicing portion for self-supportively and releasablyattaching said splicing tape to the outer surface of the underlyingwinding of said roll of sheet material substantially across the width ofsaid roll, said attachment portion being adapted for releasing at leastsaid splicing portion from the underlying winding of said roll whileleaving the outer surface of the underlying winding in a non-tackycondition, and that said method further comprises the steps of:

exposing the first part layer of said adhesive layer;

attaching said leading edge to the exposed first part layer of saidadhesive layer; and

separating said attachment portion from said splicing portion attachedto said leading edge while leaving the outer surface of said underlyingwinding in a non-tacky condition.

In addition the present invention provides a method for making a splicebetween the leading edge of a roll of sheet material and a further sheetmaterial using a splicing tape, each winding of said sheet material onsaid roll having an outer surface facing radially outwards away fromsaid roll, said splicing tape comprising:

a splicing portion and a pre-formed attachment portion, in which methodsaid splicing tape is attached to the outer surface of said underlyingwinding using said attachment portion substantially across the width ofsaid roll, characterized in that said splicing portion comprises:

an elongate backing member;

an adhesive layer on said backing member and covered by at least onerelease foil, a first part layer of said adhesive layer being providedto attach the leading edge of the roll of sheet material substantiallyacross the width of said roll to said backing member, and a second partlayer of said adhesive layer being provided for attachment to thefurther sheet material;

that said pre-formed attachment portion is connected to and distributedalong said splicing portion for self-supportively and releasablyattaching said splicing tape to the outer surface of the underlyingwinding of said roll of sheet material substantially across the width ofsaid roll; said attachment portion being adapted for releasing at leastsaid splicing portion from the underlying winding of said roll whileleaving the outer surface of the underlying winding in a non-tackycondition, and that said method further comprises the steps of:

exposing said first part layer of said adhesive layer,

attaching said leading edge to the exposed first part layer of saidadhesive layer;

exposing said second part layer of said adhesive layer,

attaching the further sheet material to the exposed second part of saidadhesive layer; and

releasing said leading edge and said splicing portion attached theretofrom said underlying winding while leaving the outer surface of saidunderlying winding non-tacky.

The present invention may provide the advantage of a splicing tape for alow step profile splice which can pass through subsequent coating andprinting machinery smoothly.

Further the splicing tape in accordance with the invention may beapplied quickly and accurately.

Additional embodiments of the invention are given in the dependentclaims.

Further advantages and embodiments of the invention are described in thefollowing with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C show various types of permanent splices.

FIGS. 2A and 2B show various types of flying splices.

FIG. 3A shows the roll preparation of a conventional flying splice.

FIG. 3B shows the roll preparation of a conventional permanent splice.

FIG. 4 shows a butt splice in accordance with the first embodiment ofthe invention.

FIGS. 5A and 5B show the first embodiment of a butt splicing tape inaccordance with the present invention;

FIGS. 6A to 6D show a second embodiment of a butt splicing tape inaccordance with the present invention;

FIG. 7 shows a conventional butt splicing tape;

FIG. 8 shows a conventional overlap splicing tape;

FIG. 9 shows a staggered overlap splicing tape.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following description of the preferred embodiments of the presentinvention the same reference signs are used for similar components ofthe splicing tape throughout the figures.

It should be noted that the thickness of adhesive layers, foils andbacking tapes have been exaggerated in the figures for clarity purposes.

FIG. 5A shows a first embodiment of the present invention constructed asa butt splicing tape in particular for forming a permanent butt splicebetween two sheet materials in particular paper. FIG. 4 shows the way inwhich the splice, according to FIG. 5A, can be made using the method ofthe invention, even when using very wide webs, and without requiringmore than one operator to make the splice. In FIG. 4 the same parts asin FIG. 3B are indicated by the same reference numbers. End 32 of thelast winding must be spliced. Splicing tape 100 is applied to the lastpreceding paper winding 31 still present on drum 30. Splicing tape 100comprises a splicing portion including a backing 1 with a pressuresensitive adhesive layer 2 on one side, as well as a first release foil11, which extends over approximately half of the width of the adhesivelayer on backing 1, and a second release foil 10 comprising a first part10', located on the remaining surface of the adhesive layer on backing1, and a second part 10", which extends beyond the longitudinal edge ofbacking 1 and which has a layer of adhesive 41 which may have arelatively light adhesive strength on the side facing the adhesive layer2, and which leaves no substantial quantities of adhesive on thesubstrate when removed. This type of adhesive layer 41 is preferably ofthe repositionable type used on the memo stickers of the "Post-It"®brand made by Minnesota Mining and Manufacturing Company, St. Paul,Minn., USA. In particular the adhesive layer 41 made be the type used onCorrection & Cover-up Tape 658® manufactured by the above Company. Theadhesive layer 41 may also be of the kind applied to Scotch Masking Tape1104® also made by the above-mentioned Company. The adhesive layer 41may be made to adhere to the release foil 10 by priming the respectivepart of the surface of the release foil 10. Further, the adhesive layer41 need not be applied continuously along the release foil 10 but may beapplied intermittently along its length.

Splicing tape 100 is temporarily attached to the last paper winding 31still on the drum with an attachment portion provided by the releasefoil 10 and the layer of adhesive 41. In this way, the smooth,non-sticky side of the splicing tape 100 facing the drum is preventedfrom moving whilst the splice is being made, and does not have to beheld in place by a large number of operators. Release foil 11 is thenremoved, as a result of which a part of the sticky side of splicing tape100 is exposed onto which web end 32 is fixed in such a way that theedge of this end is close to the edge of release foil 10. If part of theweb 32 extends over the release foil 10, it can be torn off straight, asis usual in the paper industry, at the transition between foil 11 andrelease foil 10. After this, splicing tape 100 can no longer move withrespect to the web end 32, because it is fixed to end 32. Release foil10 can now also be removed entirely, which means that the remaining partof adhesive layer 41 comes away from the underlying winding as well asthe splicing tape 100. It is preferable that, when release foil 10 isremoved, adhesive 41 leaves substantially no adhesive on the underlyingpaper winding i.e. it leaves a non-tacky surface, since this adhesivemay otherwise disrupt the way the paper is subsequently printed. It hasbeen shown that adhesives of the type mentioned above are adequate forthis, but other adhesives with this property can also be used.

After removal of release foil 10, the further end of the other web canbe fixed on the exposed part of the adhesive layer 2 of splicing tape100. Any part of the further end extending over web part 32 can again betorn off to the correct length in order to form a neat splice. For thesake of clarity, this end is not shown in FIG. 4. Covering adhesive tape6 can now simply be applied over the splice thus formed as shown in FIG.1A, preventing adhesive from splicing tape 100 from escaping via thesplice to the side of the web opposite splicing tape 100, which cancause faults when printing the paper.

An additional advantage of the method according to the invention isthat, after removing the second release foil 10, the paper reel can berotated in order, if necessary, to simplify application of the furtherend of sheet material.

The backing 1 is typically similar in strength and flexibility to thesheet materials to be joined and may be plastic or paper or any similarsheet material. When paper sheets are to be joined it is preferable ifthe backing material 1 as well as all other materials which remain inthe completed splice are repulpable and/or water soluble and/or waterdispersible. The thickness of the backing is typically in the range50-100 micro meters and the width is typically 50-100 millimeters. Thesurface of the backing 1 should preferably be coatable and/or printable.Suitable materials for joining paper rolls would be super calendered(glassine) or semi-bleached kraft paper. On one side of the backing 1 apressure sensitive adhesive (PSA) layer is applied which may becontinuous across the width of the tape as shown in FIG. 5A or mayconsist of two separate strips of adhesive with a gap there between. ThePSA may be an adhesive of the acrylic, rubber resin, silicone or similartypes. It is preferable if the PSA is repulpable. It is particularlypreferred if the PSA is a repulpable acrylic adhesive. The thickness ofthe PSA layer may be typically 2 to 100 micrometers. The PSA layer isprotected by a release foil 10, 11 which is provided with a longitudinalweakness or perforation in the middle thereof The release foils 10, 11may also be two separate release foils 10 and 11 adjacent to each otheror a single release foil which has been slit in the centre. The releasefoils may be of any suitable conventional kind, e.g. silicon or waxedpapers with a typical thickness of 30-150 micrometers. It is preferablebut not necessary for the invention if the release foils are repulpable.

The above description of the first embodiment demonstrates certainaspects of the present invention. Firstly, a portion of the splicingtape 100, namely a part of the release foil 10" and the weakly adheringadhesive layer 41, is connected to and distributed along the splicingportion 1, 2. This attachment portion 10", 41 is used to temporarilyattach the splicing tape 100 to the roll of sheet material. Theattachment portion of the splicing tape 100 is sufficient that thesplicing tape is self-supporting on the roll, i.e. when applied in astraight line it is capable of supporting its own weight without saggingor pulling.

Secondly, the attachment portion of the splicing tape 100 may beseparated from the splicing portion 1, 2 by removing the release foil 10from the PSA layer 2. This separation of the attachment portion ofsplicing tape 100 from the splicing portion 1, 2 may be carried out bydifferent means (foil 10, PSA 2) than the means for detachment of theattachment portion from the underlying sheet material (weakly adheringlayer 41). Separation of the attachment portion from the splicing tape100 may be sufficient to release the splicing portion 1, 2 from itstemporary attachment to the sheet material.

Thirdly, the attachment portion of the splicing tape may be detachedfrom the underlying sheet layer. Detachment of the attachment portionfrom the underlying sheet material may be sufficient, independent ofseparation of the attachment portion from the splicing tape 100, torelease the splicing tape 100 from its temporary attachment to the sheetmaterial.

Thus in accordance with the present invention the splicing tape 100 maybe temporarily attached to the roll of sheet material and subsequentlyreleased therefrom leaving a non-tacky outer surface of the underlyinglayer of sheet material. This outer surface is in a condition to bemachine coated and/or printed.

Embodiments with both separating and detaching means are particularlypreferred for permanent splices as the attachment portion may be removedfrom the splice area. The weakly adhering adhesive layer 41 may be arepositionable adhesive layer made from any known repositionableadhesive. For the purposes of this invention a repositionable adhesivehas a property of adhering to and being removable from the surface of asubstrate without transfer of substantial qualities of the adhesivematerial to the substrate surface. This is achieved by making theadhesion of the adhesive layer 41 to the release foil 10 (if necessaryby priming the surface of the release foil 10) considerably greater thanthe adhesion of the adhesive layer 41 to a sheet substrate. Further,after removal it is preferable if the adhesive layer retainssubstantially its adhesive properties so that it may be reapplied to thesame substrate surface. A repositionable adhesive may have a peelstrength lower than for a conventional aggressively tacky PSA. Inparticular, it is preferable if the removal of the repositionableadhesive layer from the paper substrate does not damage the surfacefibres of the paper. After detachment, printing properties of the papersurface should not be deteriorated.

FIG. 5B shows a variation of splicing tape 100 according to the firstembodiment of the invention and is made from materials similar to thosedescribed for FIG. 5A.

Release foils 10 and 11 are similar to those for the adhesive tapeaccording to FIG. 5a, but foil 10 is now approximately the same width asfoil 1--1. An additional adhesive tape 40, 41 is applied to, i.e.connected to and distributed along the free side of foil 10. Theadditional adhesive tape comprises a backing 40 and, on one face of it,the slightly adhering adhesive layer 41. Tape 40, 41 extends over theside edge of foil 10 and provides, in the same way as in FIG. 5A, theattachment portion of the splicing tape 100 for temporary attachment tothe web on reel 30.

The further adhesive tape 40, 41 is removably attached in an overlappingfashion to the release foil 10 as shown in FIG. 5B. The adhesive layer41 may be a repositionable adhesive layer 41. The backing 40 may be anysuitable backing material and is not necessarily repulpable or watersoluble as this layer is subsequently removed from the splice. It is,however, preferable if all materials used in the splicing tapes inaccordance with the invention are repulpable. The backing layer 40 istypically 15-50 mm wide. It is preferred that adhesive tape 40, 41 isCorrection & Cover-up Tape 658® or Scotch Masking Tape 1104® made byMinnesota Mining and Manufacturing Company, St. Paul, Minn., U.S.A.

The adhesive tape 40, 41 may be applied continuously on the length ofthe main splice tape 1, 2, 10, 11 or discrete lengths of the adhesivetape 40, 41 may be pre-applied intermittently, i.e. distributed, alongthe main splice tape 1, 2, 10, 11. The spacing for the intermittentstripes should be sufficient to maintain the splicing tape 100 in aself-supporting manner when applied to the roll. The surface of therelease foil 10 on the opposite side from the PSA layer 2 may be primedso that the repositionable adhesive layer 41 adheres to the primed layersufficiently for the tape to remain intact during manufacture andhandling but allowing the adhesive tape 40, 41 to be removed from therelease foil 10. This is, however, not necessary for the invention. Therelease foil 10 may be primed so that a permanent bond is producedbetween the adhesive tape 40, 41 and the release foil 10.

The application of the splicing tape as shown in FIG. 5B to the roll issimilar to that described for the splicing tape as shown in FIG. 5A.

The connection of the web end 32 is similar to the method described withrespect to FIG. 5A.

When the splice is to be made to the trailing edge of a second roll therelease foil 10 and the adhesive tape 40, 41 are removed separately ortogether so as to expose the remaining part layer of PSA 2. The trailingedge of the second roll is then aligned with the first roll 30 andattached to the splicing portion 1,2 by pressing the trailing edgeagainst the exposed PSA layer 2. Any excess sheet material of thetrailing edge can be removed by folding against the adhesive join andtearing or cutting as described above with respect to the leading edgeof the first roll. The junction between the leading and trailing edgesin the centre of the splice may then covered by a further narroweradhesive tape 6 as has been described with respect to FIG. 1A.

With the modification of the first embodiment in accordance with FIG. 5Bthe means for separating the attachment portion 40, 41 of the splicingtape 100 from the rest of the splicing tape 100 as well as the means fordetaching the attachment portion 40, 41 from the sheet material areprovided by the weakly adhering preferably repositionable adhesive layer41.

When the splicing tape 100 according to the first embodiment is used asa flying splice the width of PSA 2 under release foil 11 is normallymade narrower than the width of PSA 2 under release foil 10.

FIG. 6A shows a second embodiment in accordance with the presentinvention of a butt splicing tape 200. Instead of making use of therepositionable adhesive layer 41, 42 as described with respect to FIGS.5A to 5D the second embodiment uses a double-sided stretch releasableadhesive layer 46, 46' with a release foil 45 applied along thelongitudinal edge of the backing 1 on the opposite face from the PSAlayer 2. A stretch releasable adhesive has the property of losingtackiness when its backing material is stretched in the tapelongitudinal direction. To remove the stretch releasable tape one end ofthereof is stretched in a longitudinal direction which detackifies theadhesive at this end. The operator works, across the width of the roll,detackifying the adhesive by extending the tape. After removal noadhesive is left adhering to the surface of the underlying sheet layer.

A reusable stretch release tape is described in EP-0563057. Extension ofthe tape detackifies the adhesive coating and the tape returns to itsoriginal length on release and the adhesive regains its adhesiveproperties. Such a tape can be reapplied to the remaining splice tape 1,2, 10, 11 which can be repositioned.

A non-reusable stretch release tape is described in EP-0563272. Afterextension of the tape the adhesive is detackified but the tape remainsextended and must be discarded. The remaining splice tape 1, 2, 10, 11may be used in the same way as a conventional butt splicing tape.

The materials of the backing 1, PSA 2 and release foils 10, 11 aresimilar to those described with respect to the first embodiment. Thesplicing tape in accordance with the second embodiment of the inventionis temporarily attached to the first surface of the underlying winding31 of the roll 30 by means of the stretch releasable adhesive layer 46as the attachment portion. When the splice is to be completed thedouble-sided stretch releasable adhesive layer is extended in thelongitudinal direction parallel to splicing portion 1, 2 starting at oneend thereof. The extension of the stretch release layer 46, 46' in thisdirection detackifies the adhesive so that it no longer bonds either tothe backing layer 1 or to the underlying layer 31 of the roll 30. Thusthe stretch releasable layer 46, 46' may be removed from the splicingarea without leaving a residue of adhesive material either on thebacking material 1 or on the underlying layer 31 of the roll.

As an alternative to the second embodiment of the invention describedabove, the double sided stretch release tape may be appliedintermittently along the length of the backing 1. The stretch releasetape 46, 46' is applied so that the stretch direction of the tape isperpendicular to the longitudinal direction of the splicing tape.Extending beyond the backing 1, non-adhesive gripping portions (notshown) are provided on the ends of the lengths of stretch release tapeto enable gripping the stretch release tape. FIG. 6B shows amodification to the splicing tape 200 shown in FIG. 6A. Instead of adouble-side stretch release tape a layer of weakly adhering, preferablyrepositionable adhesive 42 with a release foil 45 is applied to, i.e.connected to and distributed along, the longitudinal edge of the backing1 below release foil 10.

The weakly adhering preferably repositionable adhesive layer 42 may beprovided by a double-sided adhesive tape with a weakly adheringpreferably repositionable adhesive layer 42 on one side and a PSA layer43 on the other. The splicing tape is constructed by attaching the PSAside 43 of this double-sided tape in the appropriate position on thebacking 1. The splicing tape 200 may then be positioned on theunderlying layer 31 as described for the second embodiment shown in FIG.6A. Alternatively, the double-sided adhesive tape may be applied to theroll using the weakly adhering, preferably repositionable layer 42 andthe splicing tape attached to the exposed PSA layer 43.

After the splicing tape 200 is positioned on the roll the leading andtrailing edges of sheet material are attached to the PSA layer 2 asdescribed above. When the sheet material is wound from the drum thesplice separates from the underlying winding along the interface of theadhesive layer 42 and the underlying winding. As the adhesive layer 42is a weakly adhering preferably repositionable adhesive the firstsurface of the underlying winding is left non-tacky. Care must be takento prevent a permanent bond between the weakly adhering adhesive layer42 and the underlying winding during storage.

FIG. 6C shows a modification of the second embodiment of the presentinvention relating to a permanent or flying butt splicing tape 200. Thesplicing tape 200 in accordance with this modification of the secondembodiment includes the splicing portion 1, 2 including a backing 1covered by an aggressively tacky pressure sensitive adhesive (PSA) 2which is itself protected by a release foil 10, 11. The release foil10,11 is provided with a longitudinal weakness, perforation or slit 60.The weakness, perforation or slit 60 is preferably arranged at aposition so that the width of the release foil 11 is smaller than therelease foil 10. On the opposite surface of the backing 1 from the PSAlayer 2 a weakly adhering, preferably repositionable adhesive layer 42is provided with its own release foil 48 at any suitable position butpreferably adjacent to the edge of the splicing tape underneath therelease layer 10 as shown. The release foil 48 may be omitted in thisembodiment. Further, several strips of repositionable adhesive 42 may beprovided across the width of the backing 1 as is shown in FIG. 6D. It isnot necessary that the repositionable adhesive layer 42 is continuousalong the length of the splicing tape 200. The adhesive may be arrangedin discrete lengths or areas therealong provided the splicing tape 200may be attached to the sheet material across the roll width by means ofthe discrete repositionable adhesive layers in a self-supporting manner.The splicing tape 200 in accordance with this modification of the secondembodiment is applied in the following way. The release foil 48 isremoved from the splicing tape, the leading edge of the first roll ofsheet material is lifted and the splicing tape is applied across thewidth of the roll or in a pattern similar to the one shown in FIG. 3A.The splicing tape is secured to the first surface of the underlyingwinding of the roll of sheet material by the repositionable adhesivelayer(s) 42. The release foil 11 is then removed exposing the PSA layer2. The leading edge of the first roll of sheet material is thencarefully laid back and is attached to the splicing tape 200 by pressingit against the PSA layer 2. Any excess of the leading edge is torn offagainst the edge of the PSA layer 2. In this condition the leading edgeof the roll of sheet material is secured to the underlying winding ofthe roll by means of the repositionable adhesive 42 and there are noexposed areas of adhesive so that the roll may be stored in thiscondition until required.

Before formation of a flying splice, the release foil 10 is removedexposing the large area of PSA 2 and the marker tape 26 is applied aswas described with respect to the conventional procedure in accordancewith FIG. 3A. The roll is then brought up to machine speed and thetrailing edge of the second roll is pressed against the exposed PSAlayer at the appropriate moment. Because the adhesion of therepositionable adhesive 42 to the underlying winding of the sheet rollis adapted to be lower than the strength of the sheet material and alsoof the adhesion of the splicing tape to the trailing edge of the secondroll, the repositionable adhesive layer 42 lifts off from the underlyinglayer of the new roll leaving no appreciable adhesive residue. Therepositionable adhesive layer 42 is designed in such a way that itsadhesion to the sheet material is considerably lower than the aggressivePSA layer 2 and its adhesion to the backing 1 is considerably greaterthan its adhesion to the sheet material of the roll.

The butt splicing tape 200 in accordance with the second embodiment mayhave both release foils 10 and 11 of the same width when the splicingtape 200 is used to make a permanent butt splice.

In accordance with the second embodiment as described with respect toFIGS. 6A-D, the attachment portion of the splicing tape 200 is providedby the adhesive layer 42. The means for detaching the attachment portion42 is provided by the adhesive layer 42 being weakly adhering,preferably repositionable. Detachment of the splice between theinterface of adhesive layer 42 and the outer surface of the underlyingsheet winding leaves this outer surface non-tacky. In theabove-mentioned embodiments the attachment portion of the splicing tapeis attached to the underlying winding of the roll by the adhesive layer41, 42, 42' and 46. However this is not necessary to the invention. Theattachment portion of the splicing tape may be temporarily andreleasably attached to the underlying winding of the roll by othermeans. The backing 1,40 or the release foil 10 may be treated withcorona discharge so that it adheres lightly to a substrate such as theunderlying winding of a roll of sheet material.

We claim:
 1. A splicing tape for splicing a leading edge of a roll ofsheet material to a further sheet material, each winding of said sheetmaterial on said roll having an outer surface facing radially outwardsaway from said roll, comprising:a splicing portion and a pre-formedattachment portion, said splicing portion comprising: an elongatebacking member; an adhesive layer on said backing member, a first partlayer of said adhesive layer being provided for attachment of theleading edge of the roll of sheet material substantially across a widthof said roll to said backing member and a second part layer of saidadhesive layer being for attachment to said further sheet material; andsaid pre-formed attachment portion being connected to and distributedalong said splicing portion for releasable and self-supportiveattachment of said splicing tape to the outer surface of an underlyingwinding of said roll of sheet material substantially across the width ofsaid roll, said attachment portion being adapted for releasing at leastsaid splicing portion from said underlying winding of said roll whileleaving the outer surface of said underlying winding in a non-tackycondition.
 2. Splicing tape according to claim 1 wherein said adhesivelayer is a first adhesive layer and said attachment portion includes:asecond adhesive layer for attachment of said splicing tape to theunderlying winding of said roll of sheet material; and releasing meansfor releasing at least said splicing portion from said underlyingwinding of said roll.
 3. Splicing tape according to claim 2, whereinsaid second adhesive layer comprises a plurality of adhesive areasapplied intermittently along said splicing portion.
 4. Splicing tape inaccordance with claim 2, wherein said releasing means includesseparating means for separating said attachment portion from saidsplicing portion.
 5. Splicing tape in accordance with claim 4, whereinsaid separating means is provided by said second adhesive layer which isa weakly adhering adhesive layer.
 6. Splicing tape in accordance withclaim 5, wherein said weakly adhesive layer is a repositionable adhesivelayer.
 7. Splicing tape in accordance with claim 4, wherein saidseparating means is provided by said second adhesive layer which is astretch releasable adhesive layer.
 8. Splicing tape in accordance withclaim 2, wherein said releasing means includes detaching means fordetaching said second adhesive layer from the outer surface of saidunderlying winding of said roll.
 9. Splicing tape in accordance withclaim 8, wherein said detaching means is provided by said secondadhesive layer which is a weakly adhering adhesive layer.
 10. splicingtape in accordance with claim 8, wherein said detaching means isprovided by said second adhesive layer which is a stretch releasableadhesive layer.
 11. A splice on a leading edge of a roll of sheetmaterial for attachment to a further sheet material, each winding ofsaid sheet material on said roll having an outer surface facing radiallyoutwards from said roll, comprising:a splicing portion and a pre-formedattachment portion, said splicing portion comprising: an elongatebacking member; an adhesive layer on said backing member, a first partlayer of said adhesive layer attaching the leading edge of the roll ofsheet material substantially across a width of said roll to said backingmember and a second part layer of said adhesive layer being provided forattachment to said further sheet material; and said pre-formedattachment portion is connected to and distributed along said splicingportion and releasably and self-supportively attaching said splicingtape to the outer surface of an underlying winding of said roll of sheetmaterial substantially across the width of said roll, said attachmentportion being adapted for releasing at least said splicing portion fromsaid underlying winding of said first roll while leaving the outersurface of said underlying winding in a non-tacky condition.
 12. Asplice according to claim 11, wherein said adhesive layer is a firstadhesive layer and said attachment portion includes:a second adhesivelayer attaching said splicing tape to the underlying winding of saidroll of sheet material; and releasing means for releasing at least saidsplicing portion from said underlying winding of said roll.
 13. A splicein accordance with claim 12, wherein said releasing means includesseparating means for separating said attachment portion from saidsplicing portion.
 14. A splice in accordance with claim 13, wherein saidseparating means is provided by said second adhesive layer which is aweakly adhering adhesive layer.
 15. A splice in accordance with claim14, wherein said weakly adhering adhesive layer is a repositionableadhesive layer.
 16. A splice in accordance with claim 13, wherein saidseparating means is provided by said second adhesive layer which is astretch releasable adhesive layer.
 17. A splice in accordance with claim11, wherein said releasing means includes detaching means for detachingsaid second adhesive layer from the outer surface of said underlyingwinding of said roll.
 18. A splice in accordance with claim 17, whereinsaid detaching means is provided by said second adhesive layer which isa weakly adhering adhesive layer.
 19. A splice in accordance with claim17, wherein said detaching means is provided by said second adhesivelayer which is a stretch releasable adhesive layer.
 20. A method forpreparing a splice between a leading edge of a roll of sheet materialand a further sheet material using a splicing tape, each winding of saidsheet material on said roll having an outer surface facing radiallyoutwards away from said roll, said splicing tape comprising:a splicingportion and a pre-formed attachment portion, in which method saidsplicing tape is attached to the outer surface of an underlying windingusing said attachment portion substantially across a width of said roll,said splicing portion comprising:an elongate backing member; an adhesivelayer on said backing member and covered by at least one release foil, afirst part layer of said adhesive layer being provided for attaching theleading edge of said roll of sheet material substantially across thewidth of said roll to said backing member and a second part layer ofsaid adhesive layer being provided for attachment to said further sheetmaterial; said pre-formed attachment portion being connected to anddistributed along said splicing portion for self-supportively andreleasably attaching said splicing tape to the outer surface of theunderlying winding of said roll of sheet material substantially acrossthe width of said roll, said attachment portion being adapted forreleasing at least said splicing portion from the underlying winding ofsaid roll while leaving the outer surface of the underlying winding in anon-tacky condition, said method further comprising the steps of:exposing the first part layer of said adhesive layer; attaching saidleading edge to the exposed first part layer of said adhesive layer; andseparating said attachment portion from said splicing portion attachedto said leading edge while leaving the outer surface of said underlyingwinding in a non-tacky condition.
 21. A method for making a splicebetween a leading edge of a roll of sheet material and a further sheetmaterial using a splicing tape, each winding of said sheet material onsaid roll having an outer surface facing radially outwards away fromsaid roll, said splicing tape comprising:a splicing portion and apre-formed attachment portion, in which method said splicing tape isattached to the outer surface of an underlying winding using saidattachment portion substantially across a width of said roll, saidsplicing portion comprising: an elongate backing member; an adhesivelayer on said backing member and covered by at least one release foil, afirst part layer of said adhesive layer being provided to attach theleading edge of the roll of sheet material substantially across thewidth of said roll to said backing member, and a second part layer ofsaid adhesive layer being provided for attachment to the further sheetmaterial; said pre-formed attachment portion being connected to anddistributed along said splicing portion for self-supportively andreleasably attaching said splicing tape to the outer surface of theunderlying winding of said roll of sheet material substantially acrossthe width of said roll, said attachment portion being adapted forreleasing at least said splicing portion from the underlying winding ofsaid roll while leaving the outer surface of the underlying winding in anon-tacky condition, said method further comprising the steps of:exposing said first part layer of said adhesive layer; attaching saidleading edge to the exposed first part layer of said adhesive layer;exposing said second part layer of said adhesive layer; attaching thefurther sheet material to the exposed second part of said adhesivelayer; and releasing said leading edge and said splicing portionattached thereto from said underlying winding while leaving the outersurface of said underlying winding non-tacky.